This commit is contained in:
2025-09-08 16:36:24 +08:00
parent 3a45b9215f
commit 6aa9e6b21f

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from typing import Dict, Optional, Any, Iterator, cast, Mapping
from langchain_core.language_models import LanguageModelInput
from langchain_core.messages import BaseMessage, BaseMessageChunk, HumanMessageChunk, AIMessageChunk, \
SystemMessageChunk, FunctionMessageChunk, ChatMessageChunk
from langchain_core.messages.ai import UsageMetadata
from langchain_core.messages.tool import tool_call_chunk, ToolMessageChunk
from langchain_core.outputs import ChatGenerationChunk
from langchain_core.runnables import RunnableConfig, ensure_config
from langchain_openai import ChatOpenAI
from langchain_openai.chat_models.base import _create_usage_metadata
def _convert_delta_to_message_chunk(
_dict: Mapping[str, Any], default_class: type[BaseMessageChunk]
) -> BaseMessageChunk:
id_ = _dict.get("id")
role = cast(str, _dict.get("role"))
content = cast(str, _dict.get("content") or "")
additional_kwargs: dict = {}
if 'reasoning_content' in _dict:
additional_kwargs['reasoning_content'] = _dict.get('reasoning_content')
if _dict.get("function_call"):
function_call = dict(_dict["function_call"])
if "name" in function_call and function_call["name"] is None:
function_call["name"] = ""
additional_kwargs["function_call"] = function_call
tool_call_chunks = []
if raw_tool_calls := _dict.get("tool_calls"):
additional_kwargs["tool_calls"] = raw_tool_calls
try:
tool_call_chunks = [
tool_call_chunk(
name=rtc["function"].get("name"),
args=rtc["function"].get("arguments"),
id=rtc.get("id"),
index=rtc["index"],
)
for rtc in raw_tool_calls
]
except KeyError:
pass
if role == "user" or default_class == HumanMessageChunk:
return HumanMessageChunk(content=content, id=id_)
elif role == "assistant" or default_class == AIMessageChunk:
return AIMessageChunk(
content=content,
additional_kwargs=additional_kwargs,
id=id_,
tool_call_chunks=tool_call_chunks, # type: ignore[arg-type]
)
elif role in ("system", "developer") or default_class == SystemMessageChunk:
if role == "developer":
additional_kwargs = {"__openai_role__": "developer"}
else:
additional_kwargs = {}
return SystemMessageChunk(
content=content, id=id_, additional_kwargs=additional_kwargs
)
elif role == "function" or default_class == FunctionMessageChunk:
return FunctionMessageChunk(content=content, name=_dict["name"], id=id_)
elif role == "tool" or default_class == ToolMessageChunk:
return ToolMessageChunk(
content=content, tool_call_id=_dict["tool_call_id"], id=id_
)
elif role or default_class == ChatMessageChunk:
return ChatMessageChunk(content=content, role=role, id=id_)
else:
return default_class(content=content, id=id_)
class BaseChatOpenAI(ChatOpenAI):
usage_metadata: dict = {}
# custom_get_token_ids = custom_get_token_ids
def get_last_generation_info(self) -> Optional[Dict[str, Any]]:
return self.usage_metadata
def _stream(self, *args: Any, **kwargs: Any) -> Iterator[ChatGenerationChunk]:
kwargs['stream_usage'] = True
for chunk in super()._stream(*args, **kwargs):
if chunk.message.usage_metadata is not None:
self.usage_metadata = chunk.message.usage_metadata
yield chunk
def _convert_chunk_to_generation_chunk(
self,
chunk: dict,
default_chunk_class: type,
base_generation_info: Optional[dict],
) -> Optional[ChatGenerationChunk]:
if chunk.get("type") == "content.delta": # from beta.chat.completions.stream
return None
token_usage = chunk.get("usage")
choices = (
chunk.get("choices", [])
# from beta.chat.completions.stream
or chunk.get("chunk", {}).get("choices", [])
)
usage_metadata: Optional[UsageMetadata] = (
_create_usage_metadata(token_usage) if token_usage and token_usage.get("prompt_tokens") else None
)
if len(choices) == 0:
# logprobs is implicitly None
generation_chunk = ChatGenerationChunk(
message=default_chunk_class(content="", usage_metadata=usage_metadata)
)
return generation_chunk
choice = choices[0]
if choice["delta"] is None:
return None
message_chunk = _convert_delta_to_message_chunk(
choice["delta"], default_chunk_class
)
generation_info = {**base_generation_info} if base_generation_info else {}
if finish_reason := choice.get("finish_reason"):
generation_info["finish_reason"] = finish_reason
if model_name := chunk.get("model"):
generation_info["model_name"] = model_name
if system_fingerprint := chunk.get("system_fingerprint"):
generation_info["system_fingerprint"] = system_fingerprint
logprobs = choice.get("logprobs")
if logprobs:
generation_info["logprobs"] = logprobs
if usage_metadata and isinstance(message_chunk, AIMessageChunk):
message_chunk.usage_metadata = usage_metadata
generation_chunk = ChatGenerationChunk(
message=message_chunk, generation_info=generation_info or None
)
return generation_chunk
def invoke(
self,
input: LanguageModelInput,
config: Optional[RunnableConfig] = None,
*,
stop: Optional[list[str]] = None,
**kwargs: Any,
) -> BaseMessage:
config = ensure_config(config)
chat_result = cast(
"ChatGeneration",
self.generate_prompt(
[self._convert_input(input)],
stop=stop,
callbacks=config.get("callbacks"),
tags=config.get("tags"),
metadata=config.get("metadata"),
run_name=config.get("run_name"),
run_id=config.pop("run_id", None),
**kwargs,
).generations[0][0],
).message
self.usage_metadata = chat_result.response_metadata[
'token_usage'] if 'token_usage' in chat_result.response_metadata else chat_result.usage_metadata
return chat_result